Hello,
I have the explanation. The problem is that there were two pages (tabs) with the same name. One was a URL link, and the other was a true page.
If you create a new page which is not a page, it is a URL, then the duplicate name is NOT checked (Advanced Settings > Link Url:). You are allowed to create this duplicate page name. This is a bug, right?
In addition, if you then update the URL page to be a regular page, no error is thrown (the condition that prevents duplicate page names to be created is not verified).
Side note: I've verified that e.g. in DNN 4.5.5 you can create a duplicated page name without issues. If someone has a legacy site with duplicate page names, it will be a problem.
I've seen that e.g. in 5.2.3 you are not allowed to create a duplicate page name at the same level. You get a friendly message "The Page Name you chose is already being used for another page at the same level of the page heirarchy."
BTW "heirarchy" is misspelled.
However, in 5.6.1 instead of this friendly message you get a not-friendly (unhanded) exception (bug?):
Error: is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Tab Exists ---> DotNetNuke.Entities.Tabs.TabExistsException: Tab Exists at DotNetNuke.Entities.Tabs.TabController.AddTabInternal(TabInfo objTab, Boolean includeAllTabsModules) at DotNetNuke.Entities.Tabs.TabController.AddTabAfter(TabInfo objTab, Int32 afterTabId) at DotNetNuke.Modules.Admin.Tabs.ManageTabs.SaveTabData(String strAction) at DotNetNuke.Modules.Admin.Tabs.ManageTabs.cmdUpdate_Click(Object Sender, EventArgs e) --- End of inner exception stack trace ---
And trying to create a duplicate page name (not in the same level) other nasty exception is thrown (the page is created anyway). bug?:
Error: is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Entities.Tabs.TabController.CreateLocalizedCopy(TabInfo originalTab, Locale locale) in F:\wwwroot\DNN561src\Library\Entities\Tabs\TabController.vb:line 1139 at DotNetNuke.Entities.Tabs.TabController.CreateLocalizedCopies(TabInfo originalTab) in F:\wwwroot\DNN561src\Library\Entities\Tabs\TabController.vb:line 1103 at DotNetNuke.Modules.Admin.Tabs.ManageTabs.SaveTabData(String strAction) at DotNetNuke.Modules.Admin.Tabs.ManageTabs.cmdUpdate_Click(Object Sender, EventArgs e) --- End of inner exception stack trace ---
I guess these two last exceptions happens just when localization is enabled and DNN is trying to copy the pages to the other languages.
Best,
Horacio.-